Actually, what Kevin wrote earlier works for me, contrary to what I thought at first.
I accomplish something similar by putting paper definitions into
various .ily files. Then just include the ones I want with \include.
It seems it's OK to have multiple \paper blocks as a result of many
\includes. Have you tried that?
I think when I first tried it, in the included files I still had variables defined as a paper block and not _just_ the paper block inside them. Something like this works well:
\book {
\score { … }
\include "paperI.ily"
\include "paperII.ily"
\include "paperIII.ily"
}
Where the included paper files are just a paper block:
\paper {
…
}
So, thanks all around! I still probably will look into the script thing in the future, that seems handy for producing several PDFs from the same source.